Devices equipped underneath a floor in a box shape are disclosed in, for example, Patent Documents 1 and 3. A device equipped on a roof in a box shape is disclosed in, for example, Patent Document 2.
Patent Document 1: Japanese Patent Application Laid-open No. 2001-258236 (FIG. 3)
Patent Document 2: Japanese Patent Application Laid-open No. H07-17396 (FIG. 3)
Patent Document 3: Japanese Patent Application Laid-open No. H05-199601 (FIGS. 1 and 2)